#include<bits/stdc++.h>
using namespace std;
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()
const int N=1e6+10;
#define INF 0x3f3f3f3f;
typedef long long int ll;
#define close(); std::ios::sync_with_stdio(false);cin.tie(0),cout.tie(0);
//----------------------------------------------------------------------------//
int a[N],sum[N];
int n,m;
int eval(int l,int r)
{
	cout << "? " << r - l + 1 << ' ';
	for(int i = l; i <= r; i ++ ) {
		if(i < r) {
			cout << i << ' ';
		}
		else {
			cout << i << endl;
		}
	}
	int res;
	cin >> res;
	return res;
}

void solve()
{
	cin >> n;
	for(int i = 1; i <= n; i ++ ) {
		cin >> a[i];
		sum[i] = sum[i - 1] + a[i];
	}
	int l = 1, r = n; 
	while(l < r) {
		int mid = l + r >> 1;
		if(eval(l, mid) == sum[mid] - sum[l - 1]) l = mid + 1;
		else r = mid;
	}
	cout << "! " << l << endl;
	return;


}

int main()
{
	close();
	int T=1; //cin>>T;
	while (T--) solve();
	return 0;
}

